The present invention relates to an apparatus for assisting in the connection of objects to be joined, and more particularly, to devices containing fusible material for connecting two or more objects which form, for example, part of an electrical circuit. Further, the present invention relates to a method for making such connections.
Presently, devices are known which contain fusible materials to assist in forming a connection. For example, U.S. Pat. No. 3,243,211 discloses a solder sleeve device defined by a hollow heat recoverable sleeve containing a fusible material. Upon insertion of one or more objects to be joined into the device, heating of the device causes the fusible material to melt and to contact the object or objects whereby upon cooling, a bonding of the objects is effected. Because an external heat source (e.g., hot air, infrared radiant source, etc.) is needed to melt the fusible material, damage of the objects to be bonded and other adjacent objects can occur due to overheating. For example, in electronics arts, such overheating can destroy delicate integrated circuits. Further the usefulness of such devices for joining wires, tubes or members which are large effective heat sinks is limited since the necessary large amounts of heat can not be transferred through the device without causing damage.
U.S Pat. No. 4,852,252 discloses a plurality of terminals already disposed in a housing of an electrical connector, including solder tails extending rearwardly from the housing which may have a thin layer of magnetic material deposited on an outer surface thereof so that respective wire ends may be placed there along with solder preforms within lengths of heat recoverable tubing may be placed there around and a high frequency current induced in a magnetic layer which then generates thermal energy sufficient to melt the solder and shrink the tubing forming terminations between the wires and the terminals. Unfortunately this structure is limited in application because the geometry of the heater is dictated by the connector contact design not by the heating requirements. The limitation of predisposing the heater material on the connector terminals at time of manufacture limits heater size, shape, location, power generation and self regulation temperature to a fixed specification. It would be advantageous to have devices that can be matched to the connection requirements i.e. power, temperature, location, etc. and do not need a connector terminal, i.e. does not need to be an integral part of the elements being connected. The present invention provides individual self heating connection devices having such advantages which also allows it to be retrofitted.
U.S. Pat. No. 4,914,267, the disclosure of which is hereby incorporated by reference in its entirety, also relates to devices which contain fusible materials to assist in forming connections. The fusible materials may be any number of meltable materials (e.g.: solders, brazing materials, heat curable potting compounds, heat flowable plastics, and so forth). As disclosed in U.S. Pat. No. 4,914,267, a hollow cylindrical autoregulating heater is incorporated into the device, the temperature of which is maintained during melting of the fusible material at a temperature not appreciably above the melting temperatures of such material. The device itself thus becomes an active element of the circuit heating itself, the fusible material and the objects to be joined or connected.
The devices disclosed therein have a continuous, hollow heater structure which completely surrounds the members to be joined limiting the scope of application of such devices. It would be advantageous to have a device not having such a geometric limitation based on an effort to achieve a closely inductively coupled heater. The present invention is an improvement over the device disclosed in U.S. Pat. No. 4,914,267 since it does not have such a spacial limitation.